arch/powerpc/kernel/machine_kexec.c

   1 /*
   2  * Code to handle transition of Linux booting another kernel.
   3  *
   4  * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
   5  * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
   6  * Copyright (C) 2005 IBM Corporation.
   7  *
   8  * This source code is licensed under the GNU General Public License,
   9  * Version 2.  See the file COPYING for more details.
  10  */
  11
  12 #include <linux/kexec.h>
  13 #include <linux/reboot.h>
  14 #include <linux/threads.h>
  15 #include <linux/memblock.h>
  16 #include <linux/of.h>
  17 #include <linux/irq.h>
  18 #include <linux/ftrace.h>
  19
  20 #include <asm/machdep.h>
  21 #include <asm/prom.h>
  22 #include <asm/sections.h>
  23
  24 void machine_kexec_mask_interrupts(void) {
  25         unsigned int i;
  26
  27         for_each_irq(i) {
  28                 struct irq_desc *desc = irq_to_desc(i);
  29                 struct irq_chip *chip;
  30
  31                 if (!desc)
  32                         continue;
  33
  34                 chip = get_irq_desc_chip(desc);
  35                 if (!chip)
  36                         continue;
  37
  38                 if (chip->irq_eoi && desc->status & IRQ_INPROGRESS)
  39                         chip->irq_eoi(&desc->irq_data);
  40
  41                 if (chip->irq_mask)
  42                         chip->irq_mask(&desc->irq_data);
  43
  44                 if (chip->irq_disable && !(desc->status & IRQ_DISABLED))
  45                         chip->irq_disable(&desc->irq_data);
  46         }
  47 }
  48
  49 void machine_crash_shutdown(struct pt_regs *regs)
  50 {
  51         default_machine_crash_shutdown(regs);
  52 }
  53
  54 /*
  55  * Do what every setup is needed on image and the
  56  * reboot code buffer to allow us to avoid allocations
  57  * later.
  58  */
  59 int machine_kexec_prepare(struct kimage *image)
  60 {
  61         if (ppc_md.machine_kexec_prepare)
  62                 return ppc_md.machine_kexec_prepare(image);
  63         else
  64                 return default_machine_kexec_prepare(image);
  65 }
  66
  67 void machine_kexec_cleanup(struct kimage *image)
  68 {
  69 }
  70
  71 void arch_crash_save_vmcoreinfo(void)
  72 {
  73
  74 #ifdef CONFIG_NEED_MULTIPLE_NODES
  75         VMCOREINFO_SYMBOL(node_data);
  76         VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
  77 #endif
  78 #ifndef CONFIG_NEED_MULTIPLE_NODES
  79         VMCOREINFO_SYMBOL(contig_page_data);
  80 #endif
  81 }
  82
  83 /*
  84  * Do not allocate memory (or fail in any way) in machine_kexec().
  85  * We are past the point of no return, committed to rebooting now.
  86  */
  87 void machine_kexec(struct kimage *image)
  88 {
  89         int save_ftrace_enabled;
  90
  91         save_ftrace_enabled = __ftrace_enabled_save();
  92
  93         if (ppc_md.machine_kexec)
  94                 ppc_md.machine_kexec(image);
  95         else
  96                 default_machine_kexec(image);
  97
  98         __ftrace_enabled_restore(save_ftrace_enabled);
  99
 100         /* Fall back to normal restart if we're still alive. */
 101         machine_restart(NULL);
 102         for(;;);
 103 }
 104
 105 void __init reserve_crashkernel(void)
 106 {
 107         unsigned long long crash_size, crash_base;
 108         int ret;
 109
 110         /* this is necessary because of memblock_phys_mem_size() */
 111         memblock_analyze();
 112
 113         /* use common parsing */
 114         ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 115                         &crash_size, &crash_base);
 116         if (ret == 0 && crash_size > 0) {
 117                 crashk_res.start = crash_base;
 118                 crashk_res.end = crash_base + crash_size - 1;
 119         }
 120
 121         if (crashk_res.end == crashk_res.start) {
 122                 crashk_res.start = crashk_res.end = 0;
 123                 return;
 124         }
 125
 126         /* We might have got these values via the command line or the
 127          * device tree, either way sanitise them now. */
 128
 129         crash_size = crashk_res.end - crashk_res.start + 1;
 130
 131 #ifndef CONFIG_RELOCATABLE
 132         if (crashk_res.start != KDUMP_KERNELBASE)
 133                 printk("Crash kernel location must be 0x%x\n",
 134                                 KDUMP_KERNELBASE);
 135
 136         crashk_res.start = KDUMP_KERNELBASE;
 137 #else
 138         if (!crashk_res.start) {
 139                 /*
 140                  * unspecified address, choose a region of specified size
 141                  * can overlap with initrd (ignoring corruption when retained)
 142                  * ppc64 requires kernel and some stacks to be in first segemnt
 143                  */
 144                 crashk_res.start = KDUMP_KERNELBASE;
 145         }
 146
 147         crash_base = PAGE_ALIGN(crashk_res.start);
 148         if (crash_base != crashk_res.start) {
 149                 printk("Crash kernel base must be aligned to 0x%lx\n",
 150                                 PAGE_SIZE);
 151                 crashk_res.start = crash_base;
 152         }
 153
 154 #endif
 155         crash_size = PAGE_ALIGN(crash_size);
 156         crashk_res.end = crashk_res.start + crash_size - 1;
 157
 158         /* The crash region must not overlap the current kernel */
 159         if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
 160                 printk(KERN_WARNING
 161                         "Crash kernel can not overlap current kernel\n");
 162                 crashk_res.start = crashk_res.end = 0;
 163                 return;
 164         }
 165
 166         /* Crash kernel trumps memory limit */
 167         if (memory_limit && memory_limit <= crashk_res.end) {
 168                 memory_limit = crashk_res.end + 1;
 169                 printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
 170                        (unsigned long long)memory_limit);
 171         }
 172
 173         printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 174                         "for crashkernel (System RAM: %ldMB)\n",
 175                         (unsigned long)(crash_size >> 20),
 176                         (unsigned long)(crashk_res.start >> 20),
 177                         (unsigned long)(memblock_phys_mem_size() >> 20));
 178
 179         memblock_reserve(crashk_res.start, crash_size);
 180 }
 181
 182 int overlaps_crashkernel(unsigned long start, unsigned long size)
 183 {
 184         return (start + size) > crashk_res.start && start <= crashk_res.end;
 185 }
 186
 187 /* Values we need to export to the second kernel via the device tree. */
 188 static phys_addr_t kernel_end;
 189 static phys_addr_t crashk_size;
 190
 191 static struct property kernel_end_prop = {
 192         .name = "linux,kernel-end",
 193         .length = sizeof(phys_addr_t),
 194         .value = &kernel_end,
 195 };
 196
 197 static struct property crashk_base_prop = {
 198         .name = "linux,crashkernel-base",
 199         .length = sizeof(phys_addr_t),
 200         .value = &crashk_res.start,
 201 };
 202
 203 static struct property crashk_size_prop = {
 204         .name = "linux,crashkernel-size",
 205         .length = sizeof(phys_addr_t),
 206         .value = &crashk_size,
 207 };
 208
 209 static void __init export_crashk_values(struct device_node *node)
 210 {
 211         struct property *prop;
 212
 213         /* There might be existing crash kernel properties, but we can't
 214          * be sure what's in them, so remove them. */
 215         prop = of_find_property(node, "linux,crashkernel-base", NULL);
 216         if (prop)
 217                 prom_remove_property(node, prop);
 218
 219         prop = of_find_property(node, "linux,crashkernel-size", NULL);
 220         if (prop)
 221                 prom_remove_property(node, prop);
 222
 223         if (crashk_res.start != 0) {
 224                 prom_add_property(node, &crashk_base_prop);
 225                 crashk_size = crashk_res.end - crashk_res.start + 1;
 226                 prom_add_property(node, &crashk_size_prop);
 227         }
 228 }
 229
 230 static int __init kexec_setup(void)
 231 {
 232         struct device_node *node;
 233         struct property *prop;
 234
 235         node = of_find_node_by_path("/chosen");
 236         if (!node)
 237                 return -ENOENT;
 238
 239         /* remove any stale properties so ours can be found */
 240         prop = of_find_property(node, kernel_end_prop.name, NULL);
 241         if (prop)
 242                 prom_remove_property(node, prop);
 243
 244         /* information needed by userspace when using default_machine_kexec */
 245         kernel_end = __pa(_end);
 246         prom_add_property(node, &kernel_end_prop);
 247
 248         export_crashk_values(node);
 249
 250         of_node_put(node);
 251         return 0;
 252 }
 253 late_initcall(kexec_setup);